Siloxane polymers for soil-repellent and soil-release textile finishes

ABSTRACT

FLUOROCARBON SILANES ARE COPOLYMERIZED WITH SILANES WHICH CONTAIN TWO OR MORE ALKYLENEOXY GROUPS. THE COPOLYMERS ARE USEFUL FOR APPLICATION TO FIBROUS MATERIALS TO PROVIDE BOTH SOIL REPELLENCY AND SOIL RELEASABILITY.

United States Patent SILOXANE POLYMERS FOR SOIL-REPELLENTS AND SOIL-RELEASE TEXTILE FINISHES Allen G. Pittman, El Cerrito, and William L. Wasley,

Berkeley, Calif., assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Application June 28, 1971, Ser. No. 157,759, which is a division of application-Ser. No. 38,899, May 19, 1970, now Patent No. 3,639,156. Divided and this application Mar. 2, 1972, Ser. No. 231,411

Int. Cl. C08f 11/04 US. Cl. 26046.5 Y 3 Claims ABSTRACT OF THE DISCLOSURE Fluorocarbon silanes are copolymerized with silanes which contain two or more al-kyleneoxy groups. The copolymers are useful for application to fibrous materials to provide both soil repellency and soil releasability.

This application is a division of our co-pending application Ser. No. 157,759, filed June 28, 1971, which in turn is a division of Ser. No. 38,899, filed May 19, 1970, now Pat. 3,639,156.

A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to and has among its objects the provision of novel polymers which are particularly useful for imparting soil-repellent and soil-release properties to fibrous materials. The objects of the invention also include procedures for treating fibrous materials with the polymers, and the treated materials as new articles of manufacture. Further objects of the invention will be evident from the following description wherein parts and percentages are by weight unless otherwise specified.

It is not generally realized that maintaining textiles in a clean state involves two different properties of the textile. One is soil repellency, that is, the ability of the textile to resist staining when it is contacted with gravy, butter, grease, or other oily substances. The other is soil releasability. Assuming that a textile has become stained, this property concerns the ease or difficulty of washing out the stains. The soil repellency and soil releasability characteristics of a given textile depend on the kind of fiber from which it is made and the kind of finishing agent which has been applied to it. Natural fibers such as cotton and wool exhibit little soil repellency, but on the other hand when they do become soiled they are readily cleaned, that is, they exhibit a high level of soil releasability. Some of the synthetics, notably polyesters, not only exhibit a low level of soil repellency but also a low level of soil releasability. Thus, the modern trend toward fabricating textiles from blends of cotton or wool with polyesters has aggravated the situation because such blends are easily soiled and the absorbed soil is difficult to wash out. The application of resins for providing durable press properties still further aggravates the soil release situation. Almost everyone has encountered a situation where a so-called wash-and-wear garment of resintreated cotton/polyester or wool/polyester blended material has become soiled by contact with an oily substance,

and it is found that it takes repeated washings to remove the stains. In efforts to circumvent these problems, fluorocarbon polymers have been applied to the textiles. Because of the oleophobic properties of most fiuorocarbons, such treatments do enhance the soil repellence of the fabric. However, they tend to make the soil release properties even worse because the aqueous washing medium cannot properly wet the fabric, hence cannot remove stains. Another remedy has been to apply hydrophilic materials, generally polymeric, to the textiles. These generally make it easier to wash out stains, but they do not enhance the ability of the textile to resist staining when contacted with oily substances. 1

A particular object of the invention is to provde the means for alleviating the problems outlined above. The invention provides polymers which confer oil repellence on fabrics so that they strongly resist staining, e.g., by oily foods or the like. Concomitantly, these polymers confer soil-release properties on the fabric to which they are applied. This means that if the fabric does become stained, the stains can be readily washed out. Another advantage is that these polymers confer anti-static properties on the fabric to which they are applied.

The polymers having this desirable combination of properties are copolymerization products of at least two different monomers, one imparting oleophobic properties, the other hydrophilic properties. More specifically, the oleophobic monomer is a silane which contains a terminal perfiuoroalkyl group of 3 to 18 perfiuorinated carbon atoms, such group being hereinafter designated as R The hydrophilic monomer is a silane which contains two or more groups of the structure -AlkO wherein Alk is an alkylene group containing 2 to 6 carbon atoms The resulting siloxane copolymers have a silicon-to-oxygen backbone, plus pendant R groups which provide oleophobicity, and groups of the structure AlkO-- which provide hydrophilicity. The monomers are described further in the following paragraphs.

The oleophobic monomer Generically, the oleophobic monomer used in accordance with the invention has the structure wherein:

R is a perfluoroalkyl group containing 3 to 18 perfiuorinated carbon atoms. This perfluoralkyl group can be of an open-chain (acyclic) configuration, straight or branched. Alternatively, it may be of a cyclic structure such as a perfiuorocyclohexyl group, or it may be a combination of acyclic and cyclic structures. Generally, the acyclic structures are preferred.

Z is a divalent bridging group linked to a carbon of R, and a carbon of (CH such as an ester (CO; or -SO an ether (O, (CH O-, or S) an amine (-(CH -NR'), or an amide or SO NR') group, wherein s is an integer from 1 to 6 and R is hydrogen or a lower alkyl radical.

R is a member of the group consisting of hydrogen, monovalent hydrocarbon radicals, and monovalent halohydrocarbon radicals. Examples of R are hydrogen; an alkyl radical such as methyl, ethyl, isopropyl, butyl, cyclohexyl, dodecyl, etc.; an aryl radical such as phenyl, tolyl, ethylphenyl, isopropylphenyl, xylyl, xenyl, naphthyl, etc.; an aralkyl radical such as benzyl or Z-phenylethyl; or a haolgenated hydrocarbon radical such as 2-chloroethy1, trifluoromethyl, 3-chloropr0pyl, 2,2,2-trifiuoroethyl, 4- chloro- (or fluoro-) cyclohexyl, p-chloro (or bromoor fiuoro-) phenyl, and the like.

Y is a member of the group consisting of halogen, alkoxy, aroxy, and acyloxy. For example, Y may be a halogen such as fluorine, chlorine, bromine, or iodine; an alkoxy radical such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, cyclohexyloxy, or the like; an aroxy radical such as phenoxy, toloxy, ethylphenoxy, isopropylphenoxy, or the like, or an acyloxy radical such as acetoxy, propionoxy, bu'tyroxy, or the like.

a is an integer from to 1.

b is an integer from 1 to 12.

n is an integer from 1 to 2.

p is an integer from 1 to 3.

q is an integer from 0 to 2, and the sum of n, p, and q is 4.

In the preferred compounds there is more than one hydrolyzable group (Y), i.e., 7 has the value 2 or 3.

These monomers are known in the art and described in the literature, for example, in Pats. 3,012,006, 3,422,131, and 3,423,234. Examples of individual monomers are given below by way of illustration, not limitation:

Of particular interest are the monomers wherein R, is the heptafiuoroisopropyl radical since this group provides a degree of olephobicity equivalent to 6 or 7 fluorinated carbons in a straight chain. Monomers of this category are disclosed in our Pat. 3,422,131 and include compounds of the structure I or CF-O-(CH i... s 32 2 Ju wherein q is an integer from 0 to 2, and the sum of n, p. and q is 4. Examples of individual monomers in this sub-category are listed below by way of illustration, not limitation:

One category of hydrophilic monomers used in accordance with the invention has the structure (III) wherein R" is a monovalent hydrocarbon radical containing 1 to 20 carbon atoms and which may be in an alkyl, aryl, or aralkyl configuration. The nature of the hydrocarbon substituent R is of no criticality; it simply serves as an inert terminator of the alkyleneoxy chain.

Alk is an alkylene group containing 2 to 6 carbon atoms.

x is an integer from 2 to 100.

R' is a divalent linking radical selected from the group consisting of -CH -CH CH -CH CH (GHQ-CH wherein: p

In the preferred monomers, there is more than one hydrolyzable group (Y), that is, d has the value 2 or 3.

The aforesaid hydrophilic monomers may be readily prepared by conventional methods. A typical procedure is to start with a nionoetherified polyalkyleneoxy glycol and convert this into the corresponding allyl (or methallyl) ether by reaction with allyl (or methallyl) bromide in the presence of a base. This intermediate is then reacted with a silane containing hydrogen attached to the silicon atom, for example, trichlorosilane, dichlorosilane, methyl dichlorosilane, or other silane of the formula H-Si wherein R, Y, c, and d are as above defined. The reaction is generally carried out in the presence of a catalyst such as chloroplatinic acid and results in addition of the silane to the unsaturated group of the allyl (or metbellyl ether},

The synthesis is illustrated by the following equations:

In the event that a methallyl halide is used in the first step, the final product is e CH:CH(CH|)CH:S1

as previously described. The synthesis is illustrated by the following formulas:

In the event the esterification is carried out with a methacrylic acid derivative, the final product is Examples of individual monomers are provided below by way of illustration:

l1 CuHzs-O-(CHz-CHz-O (CHzh-SKOCHz);

OH; H

Another category of hydrophilic monomers used in accordance with the invention contains two silyl groups, and has the structure wherein R, Y, R'", Alk, x, c, and d are as defined in Formula III; 0' is an integer from 0 to 2, d is an integer from 1 to 3, and the sum of c' and d is 3. R"" is analogous to R' in that it is a member of the group consisting of -CH -CI- I -CH -CH C a)- 2 and -(cH3 r- In preparing the compounds shown in Formula IV the same procedures are applied: as aforesaid except that the starting material is a polyoxyalkylene glycol containing two terminals hydroxyls. The synthesis is illustrated as follows:

allyl bromide ventional polymerizations used in preparing siloxane polymers. This involves subjecting a mixture of the oleophobic and hydrophilic monomers to hydrolysis. For example, the monomer mixture is stirred with an excess of water, and theri water and by-products are removed by evaporation. A preferred technique involves dissolving the monomer mixture in a solvent such as acetone, p-dioxane, tetrahydrofuran, or other volatile solvent which is at least partly miscible with water, and adding water to this solution with stirring. The reaction mixture is then subjected to evaporation, preferably under vacuum, to remove solvent, water, and by-products of the hydrolytic polymerization.

The copolymers are generally viscous liquids which are soluble in most organic solvents, particularly fluorinated solvents such as benzotri fluoride, trichlorotrifluoroethane, l,3-bistrifluoromethylbenzene, and the like. These polymer solutions are useful for treating fibrous materials to provide them with both soil repellency and soil releaseability The structure of the copolymers will vary depending on Preparation of the copolymers The copolymers of the iuveutiqn are prepared by conthe nature of the monomers selected. For example, where the monomer of Formula I is copolymerized with the monomer of Formula III, the copolymer will contain repeating units of the structure Where the hydrophilic monomer selected is according to Formula IV, the copolymer will contain repeating units as shown in Formula V and repeating units of the structure (VII) R R,

d'lao 0:11:

As noted hereinabove, we prefer to use monomers (both oleophobic and hydrophilic) wherein each contains at least 2 hydrolyzable groups per silicyl group. Such monomers yield copolymers of greater molecular weight and which are capable of further polymerizationfor example, after they are applied to a fibrous material and subjected to a curing operation. The monomers containing a single hydrolyzable group are preferably used where it may be desired to limit the degree of polymerization and thus they may be used in conjunction with dior tri-functional monomers to act as chain stoppers.

In preparing the copolymers of the invention, the proportions of the monomers may be varied depending on such factors as the number of perfluorinated carbon atoms in the oleophobic monomer, the number of alkyleneoxy groups in the hydrophilic monomer, and the properties desired'in the copolymer. In general, the monomers are used in the ratio of about 0.1 to 3 moles of the hydrophilic monomer per mole of the oleophobic monomer, with the proviso that the copolymer contain at least 10% fluorine by weight.

The copolymers of the invention encompass those which are prepared by copolymerization of the oleophobic and hydrophilic monomers as above described plus one or more monomers which are different from both of the basic reactants. The additional monomer may be employed to monomer may be dior tri-functional silanes such as methyldichlorosilane, dimethyldichlorosilane, methyltrichlorosilane, trichlorosilane, phenyldichlorosilane, trimethoxysilane, or the like.

Treatment of fibrous substrates The copolymers described herein are particularly useful for the treatment of fibrous materials, such as textiles, to provide them with oil-, water-, and soil-repellency and further to improve their soil or stain release characteristics. In practicing this phase of the invention, a copolymer is prepared as described above and applied to the fibrous substrate. Typically, the copolymer is dispersed in a liquid carrier and in this form applied to the fibrous material. The term dispersion is used in a generic sense to include solutions, suspensions, and emulsions. Where the copolymer is to be applied in the form of a solution, it is dissolved in an inert volatile solvent, e.g., benzotrifiuoride, 1,3 bis trifiuoromethyl benzene, or trichlorotrifiuoroethane. Alternatively, the copolymer is emulsified in water, with the aid of a conventional emulsifying agent. In any event, the resulting dispersion is applied to the fibrous material by a conventional dip and pad techniques. By varying the concentration of the copolymer in the dispersion and the degree of padding, the amount of copolymer deposited on the material may be varied. Typically, the amount of copolymer may be from 0.1 to 20%, based on the weight of fibrous material but it is obvious that higher or lower proportions can be used if desired. Usually, in treating textiles such as fabrics, the amount of copolymer is limited to about 0.1 to to attain the desired repellency without interference with the hand of the textile.

After application of the copolymer dispersion, the treated fibrous substrate is subjected to a conventional curing operation in order to bond the polymer to the fibers. As an example of such treatment, the fibrous material is heated in the range of about 50 to 150 C. for a period of 5 to 60 minutes. The solvent (from the copolymer dispersion) may be evaporated in a separate step prior to curing or it may simply be evaporated during the curing operation. In this curing operation the uncondensed or unhydrolyzed groups in the uncured copolymer (e.g., halo, alkoxy, or aroxy groups attached to Si) react with reactive sites in the fibers, particularly sites which contain active hydrogen as in hydroxyl, primary and secondary amide, thiol, carboxyl, and like groups. Many types of fibersfor example: wool, silk, hair, and other proteinous fibers; cotton, rayons, and other cellulosic fibers; nylon, polyurethane, and polyurea fibers-contain groups of this kind and therefore are particularly suitable substrates to obtain good bonding of the copolymer deposit. Moreover, virtually all fibrous materials, even inorganic products such as asbestos and glass fibers, contain moisture and during the curing operation this moisture promotes addi tional hydrolysis and condensation of unreacted Si-bonded halo, alkoxy, or aroxy groups with the end result that additional, in situ, polymerization occurs so that the copolymer is durably fixed to the treated substrate.

If it is desired to experite the curing operation, a conventional curing catalyst may be added to the polymer solution before application to the fibrous substrate or the catalyst may be separately deposited on the substrate before or after application of the copolymer dispersion. Typically, one may use such catalysts as zinc octoate, dibutyltin diacetate or dilaurate, triethanolarnine titanate, triethanolamine zirconate, zirconium acetate, zirconium oxychloride, zirconium or titanium esters of alkanols such as tetrabutyl titanate, zinc perfluorobutyrate, etc.

Fibrous materials treated with the copolymers of the invention display an enhanced resistance to becoming soiled and if they do become stained they can be readily cleaned. Moreover, these advantages are attained without detriment to other properties of the textile. In particular, the treatment does not impair the hand of the textile. In face, the hand is usually improved in that the textile is softer and more supple. Another point is that the improvements rendered by the process are durablethey are retained despite laundering and dry-cleaning of the product.

The invention may be utilized for improving the properties of all types of fibrous materials, for example, paper; cotton; linen; hemp; jute; ramie; sisal; cellulose acetate rayons; cellulose acetate-butyrate rayons; saponified acetate rayons; viscose rayons; cuprammonium rayons; ethyl cellulose; fibers prepared from amylose, algins, or pectins; wool silk; animal hair; mohair; leather; fur; regenerated protein fibers prepared from casein, soybean, peanut proteins, zein, gluten, egg albumin, collagen, or keratins; nylon; polyurethane fibers; polyester fibers such as polyethylene terephthalate; polyacrylonitrile-based fibers; or fibers of inorganic origin such as asbestos, glass, etc. The invention may be applied to textile materials which are in the form of bulk fibers, filaments, yarns, threads, slivers, roving, top, webbing, cord, tape, woven or knitted fabrics, felts or other non-woven fabrics, garments or garment parts.

EXAMPLES Composition 1 Nujol. 2 .65 35-Nujol and n-hexadecane, by vol. 3 n-Hexadecane. 4 n-Tetradecane. 5 n-Dodecane. 6 n-Decane. 7 n-Octane. 8 n-Heptane.

Stain release: Samples of the fabrics are stained with mineral oil, then washed and rated for stain release according to AATCC Test Method -1969. Residual stain is rated on a scale from 5 to 1 by comparison with a standard stain release replica which displays a graduated series of stains. The highest number (5) indicates complete stain removal, whereas the lowest (1) indicates virtually no stain removal.

The following oleophobic monomers were prepared by known methods:

Code desig- Monomer nation Preparation (CFa)2CFO(CH2)3SiCl2 A Patent 3,422,131.

C H; B Do.

CFs-(CF2)sCH O(CHz)aSiOla o Patent 3,012,00

The following hydrophilic monomers were prepared as described in Examples 1-5:

Monomer (wherein p is approximately 12) Example 1.Preparation of Monomer D The following reaction scheme was carried out in the preparation of Monomer D:

Into a dry l-liter, 3-necked flask, equipped with a stirrer, N inlet, dropping funnel and condenser, was placed 200 ml. of dry p-dioxane and 48 g. of 50% active sodium hydride (1 mole NaH) dispersed in mineral oil. To this was added slowly, under N 120 g. (1 mole) of the monomethyl ether of diethylene glycol.

Following this, 1 mole of allyl bromide, diluted with 100 ml. of p-dioxane, was added dropwise with stirring. The flask was cooled with ice water during the addition as considerable heat was evolved. Sodium bromide was seen to precipitate from the mixture during the addition. After all the allyl bromide had been added, the reaction mixture was stirred overnight at room temperature. The reaction mixture was then filtered free from NaBr (111 g. solid obtained), and the filtrate treated by first distilling oil? the dioxane at about 100 C. at atmospheric pressure and then distilling the product under vacuum. Seventyeight grams of the allyl ether were obtained by distillation at about 73 C. at 5 mm. Hg pressure.

Monomer D was then prepared from the allyl ether as follows: Three small, dry, Pyrex tubes sealed at one end were each charged with 2.8 g. of the allyl ether, 0.05 ml. t-butyl perbenzoate, and 3.1 ml. Cl SiH. The tubes were cooled in a Dry-Ice bath, evacuated, sealed, and placed in a steam bath overnight. The contents of the tubes were then combined and distilled under vacuum to yield 10.4 g. of Monomer D, B.P. 1l5-1l6 C. at approximately 1 mm. Hg.

Example 2.Preparation of Monomer E CH O(CH CH O) -CH SiCl (g is approximately 12) This monomer was prepared in a manner similar to that described in Example 1, using (for the preparation of the allyl ether) the following materials:

Code des- Prepaignation ration D Ex. 1.

E Ex. 2.

F Ex. 3

G Ex. 4

H Ex. 5.

225 g. of CH3O-(CH2CH2)g0H (wherein g is approximately 12) 21 g. of 50% active Nal-I is mineral oil 300 ml. p-dioxane (solvent) 100 g. allyl bromide (excess) In preparing the allyl ether, the reaction mixture was heated at C. for 24 hours rather than held overnight at room temperature.

' In the next stage of the synthesis, the following ingredients were placed in a dry, 60-ml., glass vessel:

23 g. of the allyl ether (0.04 mole) 0.15 ml. t-butyl perbenzoate 6.2 ml. Cl SiH (0.06 mole) The vessel was sealed and placed in a steam bath overnight. Then the liquid product was heated under reduced pressure to remove unreacted trichlorosilane. About 2.5 g. of unreacted Cl SiH was collected in a Dry-Ice trap, indicating good product conversion. Infrared analysis of the product, Monomer E, did not show any vinyl absorption at 6.1;/. but did show bands at 13.2 and 14.4,u., which is typical of SiCl monomers.

Monomer E could be polymerized by adding it directly to water. A water-soluble product was formed which could be cured to an insoluble cross-linked rubber on removal of water and heating at 150 C. for ca. 30 minutes.

Example 3.Preparation of Monomer F Cl Si--(CH -O(CH CH -Ol (CH SiCl The preparation of this monomer was similar to that of Monomer D except that the di-allyl ether of triethylene glycol was first prepared and followed by the addition of two moles of trichlorosilane.

In preparing the di-allyl ether the following chemicals were employed:

84 g. of a 57% active NaH- mineral oil dispersion 200 ml. dry dimethylformamide (solvent) 158 g. of triethylene glycol dissolved in ml. of dry dimethylformamide 2 moles of allyl bromide dissolved in 200 ml. of p-dioxane After addition of the allyl bromide, the slurry was heated with stirring overnight at 60 C. The salt was removed by filtration and the filtrate distilled. A crude product was obtained in a yield of 163 grams, BR C. at about 5 mm. Hg. Analysis thereof showed the desired vinyl absorption but also some residual OH which was due either to unreacted triethylene glycol or monoallyl ether. Accordingly, the crude product was treated with increments of a high molecular weight (M.W. 600) aliphatic di-isocyanate (General Mills DDI) to tie up residual OH-containing products. The di-isocyanate was added slowly, the product checked from time to time until there was no evidence of free NCO in the product. The

(wherein g is approximately 12) This monomer was prepared in the same manner as described for Monomers D and E except that the monohydroxy alcohol was a nonylphenoxy polyethylene glycol containing about 12 CH CH O- units and instead of allyl bromide, methallyl chloride was used.

Addition of methyl dichlorosilane was carried out as before, in the presence of t-butyl perbenzoate.

Example 5.Preparation of Monomer H This monomer was prepared by first adding dropwise the monomethyl ether of diethylene glycol to a two-fold excess of acryloyl chloride held at 40 C. A nitrogen purge was maintained throughout the addition and for a halfhour after the addition had been completed. After this, excess acryloyl chloride was removed under vacuum and the acrylate distilled under vacuum to obtain an 80% yield, B.P. 70-72 C. at 1.5 mm. Hg.

Trichlorosilane was added to the acrylate by heating together in a sealed tube: 0.07 mole of the acrylate, 0.2 g. of 2,6-di-t-butyl p-cresol (polymerization inhibitor), 12 ml. of HSiCl and 0.2 ml. of a 0.00014 molar solution of H PtCl -6H O in isopropanol.

Example 6.Preparation of copolymers Copolymers were generally prepared by the cohydrolysis of a mixture of the monomers, either by adding the mixture to water with vigorous stirring or, preferably, by first dissolving the mixture in a solvent such as acetone, p-dioxane, tetrahydrofuran or other solvent which is partially to completely miscible with water, then adding water to the monomer-solvent solution, and finally removing solvent under vacuum.

(A) An example follows for the copolymerization of Monomers A and D: Two ml. of Monomer A was mixed with 1 ml. of Monomer D, and the mixture added to 20 ml. of tetrahydrofuran. The solution was stirred and /2 ml. of water added. After about 1 hour, the mixture was placed on a steam bath to remove solvent. Residual solvent was removed in a vacuum oven at 80 C. at 1 mm. Hg. A clear, thick, homogenous liquid remained. This siloxane copolymer was soluble in a number of organic solvents, particularly fiuorinated solvents such as benzotrifluoride and trichlorotrifluoromethane.

The liquid polymer could be converted into an insoluble, rubbery solid by heating. For example, heating at 150 C. for 10 minutes converted a thin layer of the liquid into a rubbery solid. A true copolymer existed since a mixture of the homopolymer of A and the homopolymer of D were incompatible and formed two insoluble layers on mixing.

A series of copolymers were prepared as described in paragraph A above:

Quantity of each monomer, in ml.

Polymer code des- Monomers used ignation I II III IV V VI B and G and A C and II and A Polymer I, derived from Monomers A and D, contains recurrent units of the structures Polymer II, derived from Monomers A and D and trichlorosilane, contains recurrent units of the structures shown in Formulas VIII and IX plus HSiO' Polymer III, derived from Monomers A and E, contains recurrent units of the structure shown in Formula VIII plus CH -O-(CH CH O) (CH SiO wherein g is approximately 12.

Polymer IV, derived from Monomers A and F, contains recurrent units of the structure shown in Formula VIII plus 3(CH2)3- 1.5 Polymer V, derived from Monomers A, B, and G, contains recurrent units of the structure shown in Formula VIII plus (C'F CFO--(C'H Si(CH )O and (wherein g is approximately 12) 'Polymer VI, derived from Monomers A, C, and H, contains recurrent units of the structure shown in Formula VIII plus CF --(CF CH -O(CH SiO and Example 7.-Fabric treatment The fabrics used in the treatments were a tri-blend of wool/cotton/nylon and a tri-blend of wool/rayon/ polyester.

Treatment of the fabrics with the copolymers of the invention were carried out by immersing the fabrics in a solution of the copolymer in trichlorotrifluoroethane or 1,3-bis-trifluoromethyl-benzene. In some cases the copolymer was applied as an aqueous emulsion. After immersion in the solution or emulsion, the fabrics were run through squeeze rolls to obtain a 50-60% wet pick-up. The treated fabrics were then air-dried and cured in an oven at -150 C. for 10-20 minutes. After removal from the oven and cooling to room temperature, the products were tested for soil repellency and for soil release as previously described. In some instances the fabrics, prior to application of the copolymers, were treated with dimethylol dihydroxyethylene urea (DMDEU) in order to impart durable press properties and to examine the effectiveness of the copolymers in the presence of this conventional finishing agent. The durable press fabrics were prepared as follows: A 20% aqueous solution of DMDEU containing approximately 0.5% Zn(NO catalyst and 0.2% of a non-ionic detergent was prepared. Fabrics were 1 5 immersed in this solution, then squeezed to a wet pick-up of 40-50%. The fabric swatches were air-dried, pressed for one minute on a high-heat (350 F.) press and then cured in an oven at 325 F. for 15 minutes.

The following table summarizes the results of fabric treatment with the various copolymers described in Example 6.

tin certain cases, the copolymers were applied as aqueous emulsions. A typical example of emulsification follows: Ten grams of copolymer III was dissolved in ml. of benzotrifiuoride. To this was added 50 mg. of a commercial wetting agent (Igepal CD430, a nonylphenoxy polyoxyethylene glycol containing 6 ethyleneoxy groups per molecule). This solution was added slowly to 80 ml.

of water containing 50 mg. of a commercial wetting agent (Igepal CO-7l0, a nonylphenoxy polyoxyethylene glycol containing 12 ethyleneoxy groups per molecule) which was being stirred in a high-speed blender. The emulsion which resulted could be used as such or diluted further with water.

TABULATION OF RESULTS OF FABRIC TREATMENT Copolymer Oil repellency Code No. and Cure concentration conditions, After Stain in solution temp. 0. Before washrelease or emulsion time min. Fabric 1 washing lug rating I, 2% sol 110/10 W/C/N and a 2 5 DMDEU. Do 110 20 do s 2 a II, 2% sol 110 20 W/R/P and 5 i 5 III 37 ul 120 15 33 a 2 5 em 1v, 3% sol 110/00 w o N 2 2 4. ol 150 3 W/R/P 2 1 4 VI, 3% sol 120/10 W/R/P and 6 5 4 DMDEU. None W/C/N and 0 0 2. 5

DMDE

1 WlC/N=wool/cotton/nylon, W/R/P =wool/rayon/polyester DMDE U =dimethylol dihydroxyethylene urea.

Hereinabove we have described a series of hydrophilic monomers. These compounds may be formed into homopolymers by applying conventional hydrolytic polymerization techniques such as those described above. We have observed that these homopolymers may be applied to fibrous materials to improve their soil release properties, however, the results are not as good as those obtained by application of the aforesaid copolymers with oleophobic monomers. Of course, the homopolymers do not provide any resistance to oily staining. Taking these items into consideration, the homopolymers of the hydrophilic monomers are useful in situations where it is desired to render a fibrous material hydrophilic. They also exert a softening efiect on the substrate so that they are also useful for that purpose. In a practice of this aspect of the invention, the homopolymers are applied to the fibrous substrate in the same manner as described above in connection with the copolymers, and subjected to the same curing step. The following examples illustrate the preparation of the homopolymers and their application to textile materials.

Example 8.Polymerization of Monomer D A 2-ml. sample of Monomer D was slowly added to ml. of water. Heat was evolved during the addition. A somewhat cloudy solution resulted after completion of the addition.

A portion of the solution was placed on a glass evaporating dish and the water allowed to evaporate. A viscous polymeric siloxane was thus formed. Heating of this viscous polymer at 150 C. for 15 minutes gave a clear, rubbery, Water-insoluble film.

Example 9.Polymerization of Monomer E This monomer was polymerized by adding 1 ml. of water to 5 ml. of the monomer dissolved in 25 ml. of tetrahydrofuran. After stirring at room temperature for 1 hour, the solvent was removed under vacuum, leaving a thick water-soluble fluid polymer. This product could also be converted to a cross-linked, rubbery, water-insoluble film by heating above C.

Example 10.Treatment of textile The textile used in the following tests was a tri-blend fabric of wool/rayon/polyester which had been given a durable press treatment as follows: The fabric was immersed in a 20% aqueous solution of dimethylol dihydroxyethylene urea containing 0.5% zinc nitrate catalyst and 0.2% of a non-ionic detergent. Following this the fabric was squeezed in a pad roll to a 60% wet pick-up, air-dried, pressed for 1 minute in a hot head press (350 F.), then oven-cured at 325 F. for 15 minutes.

An aqueous solution of polymerized Monomer E was prepared by adding 5 ml. of the monomer to 95 ml. of water. After the addition, the solution was brought to neutrality by adding 1 N sodium hydroxide. A swatch of the fabric was immersed in this solution, squeezed to 60% wet pick-up, air-dried, and cured in an oven at 300 F. for 5 minutes.

The treated fabric and, as a control, a swatch of fabric which had not been treated with the polymer were then tested for stain releasability. To this end, the swatches were stained with mineral oil, washed, and rated for stain release according to AATCC Test Method 1969. Residual stain is rated on a scale from 5 to l by comparison with a standard stain-release replica which displays a graduated series of stains. The highest number (5) indicates complete stain removal, whereas the lowest (1) indicates virtually no stain removal.

The results obtained were as follows: The sample treated with the polymer had a stain-release rating of 4, whereas the control had a rating of 1.5.

Having thus described our invention, we claim:

1. A siloxane homopolymer which contains recurring units of the structure 2. A siloxane homopolymer which contains recurring units of the structure R is a monovalent hydrocarbon radical containing 1 to 20 carbon atoms,

Alk is an alkylene group containing 2 to 6 carbon atoms,

as is an integer from 2 to 100,

R is a member of the group consisting of hydrogen, monovalent hydrocarbon radicals, and monovalent halohydrocarbon radicals,

c is an integer from 0 to 2,

d is an integer from 1 to 3, and

the sum of c and d is 3.

3. A siloxane homopolymer which contains recurring units of the structure wherein: References Cited R" is a monovalent hydrocarbon radical containing 1 UNITED STATES PATENTS to 20 carbon atoms 2,846,458 8/1958 Haluska 260448.2 Allgtlsnsan alkylene group contaming 2 to 6 carbon 5 3,342,766 9/1967 Huntington 260 29 6 x is an integer fwm 2 to 100, DONAILD E. CZAJA, Primary Examiner R is a member of the group consisting of hydrogen,

monovalent hydrocarbon radicals, and monovalent M Asslstam 'Exammer halo-hydrocarbon radicals,

f 2 v 10 US. 01. X.R.

2 an g d 117-426 GS, 138.8 A, 138.8 D, 138.8 F, 138.8 N, 138.8 an 1 an UA, 139.5 A, 141, 143 A; 260-18 s, 9.2 M, 33.8 SB,

thesumofcandd1s3.

46.5 R, 46.5 UA, 824 R, 448.2 B 

